Discord has always had his way of causing mishaps and bizarre incidents, whether being a normal villain, or currently being on the path of a reformed one. But one day while he has a conversation with Fluttershy as she packs up her things for a trip to Yakyakistan, he possibly makes the worst mistake of his eternal life, even if it was out of playful mockery.
For some unknown cause, Fluttershy is stuck in her inverted state even after Discord changed the world back to normal; and she has found the means and will to travel all over Equestria for personal redemption. Who knows what kind of trouble this will cause, but Discord knows for sure that it will all be traced back to him if he can't find a way to change her back… or if she'd ever want to go back to being her timid and soft-spoken self.